German Patent No. 3 420 465 describes a device for suppressing engine knocks. In this known device, the operating parameters of the internal combustion engine are ascertained, and the respective manipulated variables for the processes to be controlled, such as ignition and injection, are determined in a control unit on the basis of these acquired operating parameters. Thus, for example, the optimal ignition firing point is calculated on the basis of speed and acting load. In the known device, provision is also made for a knock detector which determines the combustion noises individually for each cylinder. The signals from the knock detector are forwarded to a knock-signal evaluation circuit, and after filtering out the background noises, are compared there to a reference level. If a knocking combustion has been detected, then to suppress knocking, the ignition firing point in this cylinder, determined on the basis of speed and load, is retarded, thus is adjusted away from the knock limit. After a specifiable number of knock-free combustions, this altered ignition firing point is again brought forward step-wise to the manipulated variable determined by the control unit. Since there is no danger of knocking combustions when the engine is cold, it is customary to switch the knock control to the active state only after reaching a specifiable engine temperature, thus after the warm-up of the internal combustion engine. Below this enabling temperature, it is certain that no knocking can occur, since the thermal conditions in the combustion chamber do not allow it. In the known systems, the engine coolant temperature is determined for ascertaining the engine temperature.